OpenSCAD & designs
My preferred modeling software is OpenScad
Why? It's a parametric, code based 3D modelling platform. The DSL is super simple yet supports extensible design like external modules and functions. I've found it a lot easier to use for designing functional parts and models than the larger GUI-based design systems.
I currently primarily upload my models to Cults3D, which I migrated to during the great Makerbot Takeover of Thingiverse controversy of the mid 2010s. I don't personally have any beef with Makerbot, but the site got demonstrably worse and hard to use under their management. Most of my models are still there, I just tend to publish primarily elsewhere because it works better.
I might eventually put all my models on GitHub, since it natively supports rendering .STL files now, and I can better organize them there. I'll add that to this list when I do.